The invention relates to a hinge, preferably an articulated hinge, for motor-vehicle hoods, trunk lids, or the like, whose arms are connected by pivot-forming rivets, and in which spacing rings are provided between the arms.
In a known hinge of the aforesaid type (German Auslegeschrift [patent application] 1,430,250) the arms can be particularly difficult to move when the rivet joint is too rigid. The resistance to motion may result in the lateral bending of the hinge arms due to their motional operation. If, on the contrary, the rivet joint is too loose the rivet play is excessive and results in a rattling noise. Therefore, it would be necessary to adjust exactly the rivet-setting force in the formation of the head, which is difficult in view of material and element tolerances. The hinge elements are made of steel, which increases the weight of the motor vehicle.
Therefore, the object of the invention is to provide a simply manufactured, light-weight hinge whose rivet joints move easily but substantially without play.
According to a preferred embodiment of the invention, this object is achieved by the provision of at least one spacing ring made of thermoplastic material between the rivet head and the arms, and between the arms. The thickness of the spacing ring located between the arms is approximately double that of the spacing ring located between the head and the arm. The hinge elements and the rivets are made of aluminum. The size of the rivet openings in the arms is determined so that the arm is connected rigidly to the rivet on the tail (closing head) side, and pivotably on the head side. In addition the hinge is heat treated at about 130.degree. C. for approximately 30 minutes.
The primary advantage obtained from the invention is that the prestressing of the plastic spacing rings resulting from the heat treatment in the rivet-setting operation is relieved by rapid relaxation in the stable plastic deformation range, and therefore, in the entire rivet joint. Consequently, the hinge pivot joints are exposed to weak friction and substantially free of play. With this treatment the rivet-setting forces applied need not be exact. In addition the use of aluminum provides for lighter weight and the elimination of hinge element corrosion.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a single embodiment in accordance with the present invention.